Various applications exist wherein a rotating shaft extends, through a wall, into a fluid environment (and, more particularly, a liquid environment). In such applications, it is typically desirable, and even essential, that the side of the wall opposite that of the liquid environment be maintained in a dry state. That is, it is typically necessary that the wall be sealed against the passage of liquids therethrough, including occlusion around the rotating shaft or shafts.
One specific application which is illustrative of the problem is the sealing of a boat hull against passage of water in the external aqueous environment into spaces within the hull. It is, of course, necessary to preclude the leaking of water around the rudder post of a vessel, and this is true even in the case of a sailing vessel.
The problem is even more acute in the case of a power vessel. With such a boat, it is necessary to seal around not only the rudder post, but also around one or more rotating propeller drive shafts.
In the prior art, various types of resilient lip seals are used around propeller drive shafts. Typically in the prior art, they are placed in, or closely proximate, the hull flange shaft log assembly. At this location, in view of the fact that there is no bearing interface between the lip seal and the shaft, the seal can easily become misaligned. When this occurs, space, or at least a weaker seal, can occur on one side of the shaft as a result of the seal becoming displaced from an intended coaxial relationship with the shaft. When such displacement occurs, as one will be able to perceive, water can leak into the boat.
Another problem existing in the prior art is, in the case of some seals, providing adequate lubrication. Because of the resilient characteristics of the typical lip seal, it can be essential to adequate functioning and minimization of deteriorization of the seal that it be kept in a pliant state. The seal will, of course, be exposed to some water. In fact, it is the passage of the water that the seal is intended to inhibit, if not preclude. In the case of some materials, however, it is necessary that a high volume of water be provided to the seal to accomplish adequate lubrication. It is to these dictates and problems of the prior art that the present invention is directed. It is an improved sealing system which facilitates proper alignment of the seal on the rotating shaft and accomplishes adequate lubrication.